Lacticaseibacillus rhamnosus GG Improves Periodontal Bone Repair via Gut-Blood Axis in Hyperlipidemia

Periodontal bone regeneration remains a clinical challenge, and hyperlipidemia can aggravate alveolar bone resorption. Probiotics have recently been reported to improve bone mass. We aimed to determine the role of Lacticaseibacillus rhamnosus GG (LGG) in periodontal bone regeneration improvement within the context of periodontitis with hyperlipidemia. A Sprague Dawley rat model for periodontitis, hyperlipidemia, and periodontal fenestration defect was constructed (n = 36) and administered LGG gavage for 6 wk (the rats were subsequently sacrificed). Fecal microbiota from donor rats 3 wk after LGG gavage was transplanted into recipient rats to evaluate the role of LGG-modulated gut microbiota in periodontal bone regeneration. Regenerated bone mass was detected using micro-computerized tomography and hematoxylin and eosin stain. Gut microbiota was analyzed using 16S ribosomal RNA sequencing. Serum metabolites were detected by liquid chromatography-mass spectrometry (6 wk after LGG gavage). The pro-osteogenic effects of screened serum metabolite were verified in vitro on bone marrow mesenchymal stem cells (BMMSCs). We found that the bone mineral density, bone volume (BV), trabecular bone volume fraction (BV/TV), and trabecular thickness of the regenerated periodontal bone increased after LGG gavage (P < 0.05) but had little effect on oral flora. After LGG gavage, Staphylococcus, Corynebacterium, and Collinsella in the gut of donors were significantly changed, and these differences were maintained in recipients, who also showed increased trabecular thickness of the regenerated periodontal bone (P < 0.05). These key genera were correlated with BV/TV and BV (P < 0.05). In addition, LGG gavage significantly regulated bone-related blood metabolites, of which selenomethionine promoted BMMSC osteogenesis. Notably, selenomethionine was associated with key gut genera (P < 0.05). Collectively, LGG improved periodontal bone regeneration in the context of periodontitis with hyperlipidemia by modulating gut microbiota and increasing pro-osteogenic metabolites in the blood. These results reveal new insights into the use of probiotics to promote periodontal bone regeneration via the gut-blood-bone axis.

[Structural characteristics of lower respiratory tract microflora in patients with pneumoconiosis]

Objective: To explore the composition of bacteria in lower respiratory tract of patients with pneumoconiosis and dust exposure, and to compare and analyze the difference and correlation between them. Methods: From May 2020 to January 2021, a prospective multicenter cross-sectional study was conducted to select patients with pneumoconiosis who underwent bronchoalveolar lavage treatment at the Respiratory and Critical Care Medical Department of the 920th Hospital of the Joint Support Force and the Respiratory Department of Tongren Hospital in Kunming, as well as the population of dust recipients. A total of 24 patients with pneumoconiosis (pneumoconiosis group) were included, and 16 dust exposed individuals (dust exposed group) were used as controls. Two groups of patients' alveolar lavage fluid were collected. The 16SrRNA gene V3-V4 sequencing technology and bioinformatics analysis platform were used to measure and analyze the differences in microbial structure composition and associations between bacterial communities. Results: Compared with the dust exposed group, the top 5 bacterial phyla in the alveolar lavage fluid level of patients with pneumoconiosis were the same, followed by Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria, and Actinobacteria. Compared with the dust exposure group, the pneumoconiosis group patients belong to the top 5 genera of horizontal flora abundance, which are different. The dust exposure group is respectively: Pseudomonas, Proctor, Streptococcus, Achromobacter, and Neisseria. The pneumoconiosis group is respectively: Pseudomonas, Achromobacter, Streptococcus, Ralstonia, and Proctor. The Alpha diversity analysis results showed that compared with the dust exposed group, the level of bacterial diversity in the pneumoconiosis group was difference (P<0.05), and there was no statistically significant difference in bacterial evenness (P>0.05) ; Beta diversity showed differences in microbial community structure between the two groups (P<0.05 ). Single factor microbial association network analysis showed that there was a high correlation between Firmicutes and Bacteroidetes in the pneumoconiosis and dust exposed groups and other species, showing a positive correlation; The correlation between Proteobacteria and other species is high, showing a negative correlation. Conclusion: The structure and relative abundance of bacteria in lower respiratory tract were different between patients with pneumoconiosis and dust exposure, and the diversity of bacteria in lower respiratory tract increased in patients with pneumoconiosis, which may be related to disease status.

Negative associations of morning serum cortisol levels with obesity: the Henan rural cohort study

AIMS

To evaluate the associations of morning serum cortisol levels with obesity defined by different indices in Chinese rural populations.

MATERIALS AND METHODS

A cross-sectional study was performed including 6198 participants (2566 males and 3632 females). Serum cortisol was collected in morning and quantified by liquid chromatography-tandem mass spectrometry. Obesity was defined by body mass index (BMI), body fat percentage (BFP), waist-to-height ratio (WHtR), waist circumference (WC), visceral fat index (VFI) and waist-to-hip ratio (WHR). Both multivariable liner regression, logistic regression and restrictive cubic splines models were used to estimate the gender-specific relationships between cortisol levels and obesity defined by different indices, respectively.

RESULTS

After adjusting for potential confounders, serum cortisol was negatively associated with different obesity measures, except obese females defined by BFP (for instance, overall obesity defined by BMI, Quartile 4 vs. Quartile 1, odds ratio (OR) = 0.25, 95% confidence interval (CI):0.15, 0.41 in males, and OR = 0.58, 95% CI: 0.42,0.80 in females, central obesity defined by WC, OR = 0.52, 95% CI:0.39,0.69 in males and OR = 0.63, 95% CI:0.51,0.77 in females). Similarly, restrictive cubic splines showed the nonlinear relationship between high levels of cortisol and different obesity indices. Furthermore, ROC curve analysis indicated that cortisol could improve the discrimination of model with common biomarkers.

CONCLUSION

Morning serum cortisol were negatively related to obesity defined by different indices in Chinese rural populations. In addition, cortisol could be as a biomarker for prediction of obesity in males.

[Analysis of Dimethyltryptamine in Captured Suspicious Substances：Three Case Reports]

Abstract.

An algorithm to simulate nonstationary and non-Gaussian stochastic processes

We proposed a new iterative power and amplitude correction (IPAC) algorithm to simulate nonstationary and non-Gaussian processes. The proposed algorithm is rooted in the concept of defining the stochastic processes in the transform domain, which is elaborated and extend. The algorithm extends the iterative amplitude adjusted Fourier transform algorithm for generating surrogate and the spectral correction algorithm for simulating stationary non-Gaussian process. The IPAC algorithm can be used with different popular transforms, such as the Fourier transform, S-transform, and continuous wavelet transforms. The targets for the simulation are the marginal probability distribution function of the process and the power spectral density function of the process that is defined based on the variables in the transform domain for the adopted transform. The algorithm is versatile and efficient. Its application is illustrated using several numerical examples.

Association of obesity with bone mineral density and osteoporosis in adults: a systematic review and meta-analysis

OBJECTIVES

Results from previous studies investigating the association of obesity with bone mineral density (BMD) and osteoporosis (OP) are inconsistent. The purpose of the present study was to examine whether obesity is associated with BMD and the risk of OP.

STUDY DESIGN

This is a meta-analysis.

METHODS

A computerised literature search was conducted using the PubMed, Web of Science, China National Knowledge Internet (CNKI) (Chinese) and Wanfang (Chinese) databases for relevant articles published in English or Chinese before the end of December 2017. Means with standard deviations and odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs) were computed to estimate the association between obesity and BMD and the risk of OP by using a random-effects model. In addition, a heterogeneity test and sensitivity analysis were conducted.

RESULTS

Adults with obesity had higher BMD than healthy-weight subjects in both the lumbar spine and femoral neck measurement sites. Obesity was positively related to BMD in the two sites, with merged weighted mean difference (WMD) of 0.07 g/cm² in the lumbar spine (95% CI: 0.045, 0.095; P < 0.001; P_{heterogeneity} <0.001; I² = 89.1%) and WMD of 0.087 g/cm² in the femoral neck (95% CI: 0.063, 0.112; P < 0.001; P_{heterogeneity} <0.001; I² = 92.8%). General obesity was negatively related to femoral neck OP, indicating that obesity is a protective factor for OP, with a merged OR of 0.169 (95% CI: 0.132, 0.216; P < 0.001; P_{heterogeneity} = 0.716; I² = 0.0%).

CONCLUSIONS

Adults with obesity had significantly higher BMD than healthy-weight adults. Obesity was positively associated with BMD and negatively correlated with OP.

Lipid profiles as potential mediators linking body mass index to osteoporosis among Chinese adults: the Henan Rural Cohort Study

This study is to examine the relationship between body mass index (BMI) and osteoporosis in rural areas of China, and then explore whether this association was mediated by lipid profiles. Results showed that with the increasing of BMI, the risk of osteoporosis was reduced, and lipid profiles mediate this association.

INTRODUCTION

To examine the relationship between BMI and osteoporosis, and explore whether this association was mediated by lipid profiles.

METHODS

A total of 8272 participants (18-79 years) were enrolled from the Henan Rural Cohort Study. The bone mineral density of the calcaneus was measured using an ultrasonic bone density apparatus. Logistic regression and restricted cubic splines were used to evaluate the odds ratio (OR) and 95% confidence intervals (95% CI). Mediation analysis using bootstrap was performed to examine the contribution of lipid profiles to BMI-related osteoporosis.

RESULTS

The crude and age-standardized prevalence of osteoporosis were 15.93% and 11.77%, respectively. The mean BMIs were 24.12 kg/m² for participants with osteoporosis and 25.06 kg/m² for non-osteoporosis participants (P < 0.001). After adjusting for potential confounders, subjects with obesity had a lower OR of osteoporosis (0.493 [95% CI: 0.405-0.600], P_trend < 0.001) compared with normal-weight individuals. Mediation analysis showed that lipid profile partly mediated the relationship between BMI and osteoporosis with indirect effect OR (95% CI) of 0.985 (0.978-0.992), and the proportion explained of BMI was 15.48% for lipid profile.

CONCLUSION

With the increasing of BMI, the risk of osteoporosis was reduced in the Chinese adult population, and lipid profiles may be a potential mediator linking reduced risk of osteoporosis. Elucidating the underlying mechanisms will facilitate developing feasible preventive and therapeutic measures for osteoporosis. Chinese clinical trial register: ChiCTR-OOC-15006699.

Associations of serotonin receptor gene HTR3A, HTR3B, and HTR3A haplotypes with bipolar disorder in Chinese patients

Single nucleotide polymorphisms (SNPs) in HTR3A and HTR3B have been reported to be associated with bipolar disorder in European and Japanese populations. We explored the roles of 21 tag SNPs in HTR3A and HTR3B in susceptibility to bipolar disorder in a Chinese cohort. Twenty-one Tag SNPs were genotyped in a study consisting of 130 patients with bipolar disorder, who visited Shandong Mental Health Center between June 2013 and May 2014, and 109 healthy individuals as controls. All of the tag SNPs were genotyped using Sequenom MassArray matrix-assisted laser desorption/ionization time of flight spectrometry. Plink 1.07, Haploview 4.2, and SPSS 20.0 were used for the analysis of the genotypes and the associations of the haplotypes with bipolar disorder. Association analyses of tag SNPs detected significant associations with the A allele in HTR3A rs1176719 (P = 0.030) and the C allele in HTR3A rs1176713 (P = 0.048). Haplotype-based association analyses indicated a statistically significant (P = 0.035) five-SNP haplotype (rs1062613:C, rs11604247:C, rs1176722:G, rs2276302:A, rs1176719:G) of linkage disequilibrium in block 3. Analysis of our small Chinese sample revealed a significant association of HTR3A with bipolar disorder, but yielded no evidence of an association between HTR3B and bipolar disorder. Furthermore, evidence for an association was found for a haplotype of HTR3A. Studies with larger Chinese samples are needed to verify our findings.

[In vitro study of biological characteristics of new retrograde filling materials iRoot]

OBJECTIVE

To study the biological characteristics of new retrograde filling materials iRoot BP plus and iRoot FS.

METHODS

(1) The roots were cut into 3 mm in length, and the root canals were prepared to 1 mm in diameter, followed by being filled with iRoot BP plus, iRoot FS, or mineral trioxide aggregate (MTA). The specimens were immersed in simulated body fluid (SBF). The ability of mineralization in vitro was detected through three studies. First, the mineralization of specimens was analyzed through scanning electron microscope observations and energy dispersive X-ray spectrometer. Then, the pH of SBF was monitored using pH meter. (2) The extracts were gained by immersing blocks of iRoot BP plus, iRoot FS, and MTA (8 mm diameter and 2 mm height) into dulbecco's modified eagle medium (DMEM). The effects of the extracts on proliferation of MG63 cells were detected through MTT assay. The gene expression level of alkaline phosphatase (ALP) was analyzed by quantitative real-time PCR, and the expression of ALP activity was observed by ALP activity staining.

RESULTS

(1) The formation of minerals could be observed on the surfaces of iRoot BP plus, iRoot FS, and MTA at the end of 24 h, and there were more amounts of apatite aggregated after 14 days. The values of Ca/P ratios of apatites were 1.43, 1.39, and 1.51, respectively. (2) The pH of SBF could be raised to 8.09±0.07, 7.91±0.06, and 8.11±0.06, respectively, significantly higher than the blank. (3) The extracts of iRoot BP plus, iRoot FS, and MTA of dilutions of 1:5 and 1:10 presented no effect of proliferation of MG63 cells. (4) iRoot BP plus and iRoot FS could significantly up-regulated the levels of ALP messenger RNA expression, while there was no obvious difference in ALP staining among the iRoot BP plus, iRoot FS, MTA, and the blank.

CONCLUSION

The present study shows that iRoot has displayed good mineralization capability in vitro and capability to promote differentiation and mineralization of MG63 cells, inferring that iRoot may have good bioactivity.

Increased extracellular dopamine and 5-hydroxytryptamine levels contribute to enhanced subthalamic nucleus neural activity during exhausting exercise

The purpose of the study was to explore the mechanism underlying the enhanced subthalamic nucleus (STN) neural activity during exhausting exercise from the perspective of monoamine neurotransmitters and changes of their corresponding receptors. Rats were randomly divided into microdialysis and immunohistochemistry study groups. For microdialysis study, extracellular fluid of the STN was continuously collected with a microdialysis probe before, during and 90 min after one bout of exhausting exercise. Dopamine (DA) and 5-hydroxytryptamine (5-HT) levels were subsequently detected with high-performance liquid chromatography (HPLC). For immunohistochemistry study, the expression of DRD2 and HT2C receptors in the STN, before, immediately after and 90 min after exhaustion was detected through immunohistochemistry technique. Microdialysis study results showed that the extracellular DA and 5-HT neurotransmitters increased significantly throughout the procedure of exhausting exercise and the recovery period (P<0.05 or P<0.01). Immunohistochemistry study results showed that the expression levels of DRD2 and HT2C in the rat STN immediately after exhausting exercise and at the time point of 90 min after exhaustion were both higher than those of the rest condition, but the difference was not significant (P>0.05). Our results suggest that the increased extracellular DA and 5-HT in the STN might be one important factor leading to the enhanced STN neural activity and the development of fatigue during exhausting exercise. This study may essentially offer useful evidence for better understanding of the mechanism of the central type of exercise-induced fatigue.

Glans-reconstruction with preputial flap is superior to primary closure for post-surgical restoration of male sexual function in glans-preserving surgery

We conducted this study to investigate whether glans-reconstruction with preputial flap would be more helpful for post-operative restoration of patients' sexual potency than primary closure. From 2007 to 2013 at four centres, 46 cases reconstructed with preputial flap and 59 with primary closure were selected for the investigation from 142 consecutive cases of superficial glans cancer, with the largest diameter of lesion ≤2.5 cm, who undergoing glans-preserving surgery (GPS). Subjective evaluation for patients' sexual performance was investigated using the International Index of Erectile Function-15. Objective evaluation was carried out by the Audio Visual Sexual Stimulation test with RigiScan-Plus. The degree of satisfaction for penile appearance and patients' confidence and partners' acceptability for intercourse were evaluated by 5-point scales. Patients with preputial flap reconstruction showed significant better performance in three domains (orgasmic function, intercourse satisfaction and overall satisfaction, all p < 0.05) and significantly higher ratios of appearance satisfaction (78.3% vs. 57.6%, p = 0.026) and intercourse confidence (69.6% vs. 49.2%, p = 0.035) compared with those undergoing primary closure at post-operative month 6 ends. Their sexual partners in the preputial flap group also exhibited significantly higher ratios of appearance satisfaction than in the primary closure group (67.4% vs. 42.4%, p = 0.011). Reconstruction with preputial flap contributes to a more acceptable cosmetic appearance of the penis and minimizes post-operative negative psychological impediments. Patients can benefit more from reconstruction with preputial flap than primary closure. Glans-reconstruction with preputial flap should be considered the primary reconstruction technique in GPS.

Synthesis and Characteristics of Graft Copolymerization of Starch-G-PAM Using A Twin-Roll Mixer as Reactor for Cornstarch with Different Amylose/Amylopectin Ratios

Starch-based superabsorbent polymers (SAPs) were produced by graft copolymerization of starch-g-acrylamide using a twin-roll mixer as reactor. This work focused on the effect of starch microstructure (amylose/amylopectin contents) from the same source (corn starch) on the graft ratio (GR), graft efficiency (GE) and Add-on (AO), as well as water absorption capability (WAC) of the SAPs, which were investigated by FTIR, NMR, gravimetric and TGA. The torque variation represented all the processing in the reactor, including compress, gelatinization, graft reaction and crosslinking. Results showed that all the starches were successfully grafted with acrylamide then crosslinked by N.N′-methylene-bisacrylamide through this technology. Both AO and GR increased with increasing amylose content. But the GE decreased with increasing amylose content, which is different from the results in the solution reaction. The higher WAC of high amylose starch-based SAP corresponds with higher AO and GR, while the higher WAC of waxy-based SAP corresponds with higher GE.

ESAT-6- and CFP-10-specific Th1, Th22 and Th17 cells in tuberculous pleurisy may contribute to the local immune response against Mycobacterium tuberculosis infection

Th1 cell-mediated adaptive immune response is very important but may not be sufficient to control Mycobacterium tuberculosis (M. tuberculosis) infection. The roles of the various T cell subsets and cytokines in the inflammatory processes are not clearly elucidated. We investigated whether Th1, Th22 and Th17 cells mediated cellular immunity at the local site of M. tuberculosis infection in patients with tuberculous pleurisy (TBP). The results showed that the cytokines IFN-γ and IL-22 but not IL-17 were elevated in tubercular pleural fluid. Following stimulation with immune-dominant peptides of early secreted antigenic target-6 (ESAT-6), culture filtrate protein-10 (CFP-10) or Bacille Calmette-Guerin, pleural fluid mononuclear cells expressed high levels of cytokines IFN-γ, IL-22 and IL-17 as revealed by mRNA and protein measurements. In addition, we showed that cytokines IFN-γ, IL-22 and IL-17 were produced in M. tuberculosis-specific immune response by distinct subsets of CD4+ T cells with the phenotype of CD45RA-CD62L-CCR7+CD27+ . Our results demonstrated for the first time that ESAT-6- and CFP-10-specific Th1, Th22 and Th17 cells existed in the patients with TBP and might play an essential role against M. tuberculosis infection. The findings of this study raised the possibility of unravelling the critical targets for therapeutic intervention in chronic inflammatory diseases such as TBP.

MicroRNA-25 functions in regulation of pigmentation by targeting the transcription factor MITF in Alpaca (Lama pacos) skin melanocytes

Although the influence of endocrine factors is well established, the molecular and cellular mechanisms controlling coat color are not completely understood. A major mechanism for post-transcriptional regulation of gene expression is through the action of microRNAs (miRNAs), which anneal to the 3' untranslated region of mRNAs in a sequence-specific fashion and either block translation or promote transcript degradation. In this study, we investigated the expression of miRNAs in the skin of alpacas with brown vs white coat color using a microarray screen; identified potential mRNA targets for identified miRNAs among coat color genes; and subsequently determined the ability of a specific, differentially expressed miRNA (miR-25) to suppress expression of micropthalmia-associated transcription factor (MITF), a predicted miR-25 target gene that regulates genes linked to coat color. Expression of 10 different miRNA species in the skin of alpacas with brown vs white coat color was identified from microarray screens. Of the 10 alpaca skin miRNAs identified, predicted binding sites in the 3' untranslated region of RNAs encoding for known genes linked to coat color were primarily for miR-25, but sites were also identified for miR-129 and miR-377. Potential miR-25 binding sites were present in transcripts encoding for 11 coat color genes, including MITF. An inverse relationship between transcript abundance for MITF and miR-25 was observed in skin samples collected from alpacas with white vs brown coat color. Furthermore, overexpression of miR-25 in cultured melanocytes reduced MITF mRNA and protein abundance and corresponding mRNA abundance for the MITF-regulated enzymes tyrosinase and tyrosinase-related protein 1. Results support a novel functional role for miRNA-25 in the regulation of gene expression linked to coat color.

Efficient fluorescence-based imaging methods for quantitating infectivity and oncolytic efficacy of Newcastle disease virus

A high throughput quantitation protocol is desired to determine the replication of various recombinant oncolytic viruses in vitro. Plaque assay is the classic method for viral infectivity quantitation but is laborious and time consuming; moreover it does not report the oncolytic efficacy of a virus. In this paper, three new imaging methods for quantitating viral infectivity are derived and evaluated: fluorescence intensity, infection counts, and infection degree. Infection of oncolytic Newcastle disease virus in human tumor and normal cells was followed over a time course by plaque assay and the imaging methods. For the latter, brightfield and green channel images were acquired at various fixed locations in the cell culture, and later analyzed. One of the imaging methods was found to be highly correlated with viral titer; the other methods are complementary to plaque assay and provide additional information like oncolytic efficacy, syncytium formation etc. The new methods significantly reduce the time and material costs required by plaque assay, and provide an efficient system for quantitating and characterizing infectivity and efficacy of oncolytic viruses.

Influence of intermittent anaerobic exercise on mouse physical endurance and antioxidant components

OBJECTIVE

To determine the effect of intermittent anaerobic exercise on physical endurance, antioxidant capacity, and lipid peroxidation of brain, heart, and skeletal muscles in mice.

METHODS

Mice were made to perform intermittent (with short or long rest intervals) anaerobic swimming on six consecutive days. Body weight was monitored. Tissue total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and thiobarbituric acid reaction substance (TBARS) were determined on the 2nd, 4th, and 6th day. Physical endurance was determined on day 7 by using an exhaustive swimming test and a static grasping test.

RESULTS

The intermittent anaerobic exercise resulted in decreased growth rate and physical endurance capacity, as indicated by less weight gain and shorter time to exhaustion during the exhaustive swimming and static grasping test (p<0.05). It also led to a higher T-AOC in muscle, heart, and brain, higher SOD activity in muscle and heart, and higher TBARS content in muscle (p<0.05). This type of exercise had no effect on brain SOD and TBARS. The changes in T-AOC in brain, muscle, and heart were all more pronounced the longer the experiment continued (p<0.05).

CONCLUSION

Intermittent anaerobic exercise reduced growth and physical endurance and increased tissue antioxidant capacity and lipid peroxidation.

Perinatal exposure to environmental tobacco smoke upregulates nicotinic cholinergic receptors in monkey brain

In humans, perinatal exposure to environmental tobacco smoke (ETS) is associated with neurobehavioral deficits. In the current study, we exposed Rhesus monkeys to ETS in late gestation and in the early neonatal period, and examined changes in neurotransmitter receptors in the brainstem and caudal portion of the cerebral cortex. Nicotinic acetylcholine receptors were markedly upregulated and the effect was selective in that there were no changes in m(2)-muscarinic acetylcholine receptors or in beta-adrenergic receptors. Nicotinic receptor upregulation is indicative of chronic cell stimulation by nicotine, and is a hallmark of nicotine-induced neuroteratogenesis. These results indicate that perinatal ETS exposes the fetus and neonate to quantities of nicotine that are sufficient to alter brain development.

Developmental neurotoxicity of chlorpyrifos modeled in vitro: comparative effects of metabolites and other cholinesterase inhibitors on DNA synthesis in PC12 and C6 cells

The widely used organophosphate pesticide chlorpyrifos is a suspected neuroteratogen. In the current study, we compared the effects of chlorpyrifos and its major metabolites in two in vitro models, neuronotypic PC12 cells and gliotypic C6 cells. Chlorpyrifos inhibited DNA synthesis in both cell lines but had a greater effect on gliotypic cells. Chlorpyrifos oxon, the active metabolite that inhibits cholinesterase, also decreased DNA synthesis in PC12 and C6 cells with a preferential effect on the latter. Trichloropyridinol, the major catabolic product of chlorpyrifos, had a much smaller, but nevertheless statistically significant, effect that was equivalent in both cell lines. Diazinon, another organophosphate pesticide, also inhibited DNA synthesis with preference toward C6 cells, but was less effective than was chlorpyrifos. Physostigmine, a non-organophosphate cholinesterase inhibitor, was less effective than either chlorpyrifos or diazinon, but still caused significant inhibition of DNA synthesis in C6 cells. We also found that the addition of sera protected the cells from the adverse effects of chlorpyrifos and that the effect could be reproduced by addition of albumin. These results indicate that chlorpyrifos and other organophosphates such as diazinon have immediate, direct effects on neural cell replication, preferentially for gliotypic cells. In light of the protective effect of serum proteins, the fact that the fetus and newborn possess lower concentrations of these proteins suggests that greater neurotoxic effects may occur at blood levels of chlorpyrifos that are nontoxic to adults.

Deoxycholic acid suppresses p53 by stimulating proteasome-mediated p53 protein degradation

Bile acids, principally deoxycholic acid (DCA), have been implicated in the promotion of colon tumorigenesis in both animals and humans. Increasing evidence suggests that bile acids may exert their tumor promoting activity by modulating intracellular signaling and altering gene expression. In this study we have investigated the effect of bile acids on the tumor suppressor p53 using the human colon tumor cell line HCT116, which retains the wild-type p53 gene and functional p53 signaling in response to DNA damage. We found that exposure of the cells to elevated concentrations of DCA suppressed accumulation of p53 protein as well as p53 transactivation and impaired the p53 response of the cells to DNA damaging agents, such as ionizing radiation. Neither ursodeoxycholic acid, a putative chemopreventive agent, nor cholic acid, which is biologically inert, had any effect on p53 protein level and transactivation activity. Further examination revealed that instead of inhibition, DCA induced p53 mRNA in a dose-dependent manner, indicating that the inhibitory effect of DCA on p53 protein is mediated by a post-transcriptional mechanism. Both lactacystin, a specific inhibitor of the 26S proteasome, and leptomycin B, a specific inhibitor of the nuclear export protein CRM1, could block the effect that DCA had on p53 protein levels, suggesting that DCA suppressed p53 by stimulating the process of proteasome-mediated degradation of p53. Significantly, blocking extracellular signal-regulated kinase (ERK) signaling, but not protein kinase C (PKC), blunted suppression by DCA of p53 protein levels and transactivation activity, suggesting that DCA suppressed p53, in part, by stimulating the ERK signaling pathway. Both ERK and PKC signaling have been previously demonstrated to be stimulated by DCA. These results suggest a novel signaling mechanism of bile acids that may play an important role in colon tumor promotion mediated by bile acids.

Activation and role of mitogen-activated protein kinases in deoxycholic acid-induced apoptosis

The bile acid deoxycholic acid (DCA) is a known tumor promoter and it has been suggested that DCA-induced apoptosis plays an important role in colon tumor development. In this study we have characterized the capacity of DCA to stimulate mitogen-activated protein kinase (MAPK) activity and examined the effect that MAPK activity had on DCA-induced apoptosis. Analysis of MAPK activity in DCA-treated HCT116 cells using phosphorylation-specific antibodies and in vitro kinase assays indicated that both the extracellular signal-regulated kinase (ERK) and p38 MAPK (p38), but not the c-Jun N-terminal kinase (JNK), were activated. Using pharmacological inhibitors we determined that only ERK could influence DCA cytotoxicity and that elevated ERK activity could suppress DCA-induced apoptosis. This observation was confirmed genetically. Suppressing ERK activity by overexpressing a dominant negative form of the ERK MAP kinase resulted in increased sensitivity to DCA-induced apoptosis whereas elevated ERK activity artificially produced by overexpression of the wild-type ERK kinase blunted DCA-induced apoptosis. Taken together, our results suggest that DCA can stimulate pro-apoptotic and anti-apoptotic signaling pathways and that sensitivity to DCA-induced apoptosis can be modulated by the ERK MAP kinase.

Conformational phenotype of p53 is linked to nuclear translocation

P53 is inactivated in tumors by mechanisms other than mutations in the p53 gene itself. To gain insight into the mechanisms by which this inactivation occurs, we chemically mutagenized A1-5 cells expressing high levels of temperature sensitive p53val135 (tsp53) and selected for clones that were capable of growth at the permissive temperature for p53 activation. We expanded 22 clones (ALTR cells for A1-5 Low Temperature Resistant) that could grow at the permissive temperature. Most exhibited cytoplasmic sequestration as the mechanism by which p53 was inactivated. We show here that this cytoplasmically sequestered tsp53 protein is maintained in a mutant conformation. Only in clones with nuclear localized p53 is it also expressed in the wild-type conformation suggesting that subcellular localization of tsp53 is important in determining the conformation of the protein. Consistent with this, we show that the changes in conformation of p53 in A1-5 and SK-N-SH cells induced by ionizing radiation also correlate with nuclear translocation of p53. We suggest that nuclear translocation of p53 can result in a change in the conformation from mutant to wild-type but that these may be two separable events. Oncogene (2000) 19, 4042 - 4049.

Bile acid-induced activation of activator protein-1 requires both extracellular signal-regulated kinase and protein kinase C signaling

Elevated concentrations of fecal bile aids are known to promote colon cancer and increasing evidence suggests that alterations in cellular signaling and gene expression may play an important role in this process. In this study, we examined the molecular mechanisms underlying bile acid-mediated gene regulation using GADD153 as our model gene. Promoter deletion analyses revealed that the activator protein-1 (AP-1) transcription factor was crucial for deoxycholic acid (DCA)-mediated GADD153 gene transcription. Electrophoretic mobility shift assays and transient transfection analyses demonstrated that both DNA binding and transactivation activities of AP-1 were induced by DCA in a dose-dependent manner. The AP-1 complex induced by DCA consisted of JunD, Fra-1, and c-Fos. Examination of the signaling pathways stimulated by DCA showed that extracellular signal-regulated kinases (ERKs) were required for AP-1 activation. Inhibition of ERK by the mitogen-activated protein kinase/ERK kinase inhibitor PD 98059 or by expression of a dominant negative mutant ERK suppressed AP-1 activation. Notably, the PKC inhibitor, calphostin C, also abolished DCA-induced AP-1 activation but did not affect DCA-mediated ERK activation, suggesting that ERK and PKC function in separate signaling pathways that cooperatively mediate DCA-induced AP-1 activation. Hence, bile acid-stimulated signaling appears to converge on the AP-1 protooncogene.

No correlation of polymorphism of angiotensin-converting enzyme genes with left ventricular hypertrophy in essential hypertension

To investigate the correlation of polymorphism of angiotensin-converting enzyme (ACE) genes with left ventricular hypertrophy in essential hypertension, 151 patients with essential hypertension were studied. ACE genotypes were determined by PCR technology and diastolic left ventricular diameter (DLVd), systolic left ventricular diameter (SLVd), interseptal ventricular thickness (IVS), and left ventricular posterior wall thickness (LVPW) were scanned by echocardiography. Left ventricular mass (LVM) and the left ventricular mass index (LVMI) were calculated from echocardiographic findings. Results revealed that DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the DD genotype group were 49.9 +/- 5.6 mm, 30.5 +/- 6.5 mm, 11.2 +/- 1.6 mm, 11.7 +/- 1.5 mm, 259.5 +/- 62.1 g, 92.7 +/- 23.5 g/m2, respectively. DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the ID genotype group were 8.9 +/- 5.3 mm, 31.5 +/- 5.2 mm, 11.4 +/- 1.7 mm, 11.9 +/- 1.6 mm, 261.3 +/- 70.3 g, and 94.9 +/- 25.8 g/m2, respectively, and DLVd, SLVd, IVS, LVPW, LVM, and LVMI of the II genotype group are 48.9 +/- 5.5 mm, 31.8 +/- 6.5 mm, 11.1 +/- 1.9 mm, 11.5 +/- 1.8 mm, 250.8 +/- 82.5 g and 90.8 +/- 30.1 g/m2 respectively. There was no significant difference between the ID, DD and II genotype groups as regards DLVd, SLVd, IVS, LVPW, LVM, and LVMI (p > 0.05). These findings indicate that there is no association between the ACE gene and left ventricular hypertrophy in essential hypertension occurring in the Chinese population.

General Green's functions for SAW device analysis

The traditional Green's function has been widely used to analyze surface acoustic wave (SAW) devices for many years because of its physical basis and its ability to model many propagating modes. Simplifications are, however, introduced in the derivation of the traditional Green's function that cause it to ignore some important effects, such as mass loading caused by surface electrodes. Recently, a generalized Green's function was introduced that is able to include mechanical loading effects. Based on previous work by E.L. Adler (1994) and R.C. Peach (1995), we use concise matrix notation to deduce the generalized Green's functions that describe the effects of surface stresses and electrical displacement on the three mechanical displacement components and on the electrical potential. Effective permittivities of 15 materials/cuts and the 16-element Green's functions for two materials are presented.

A novel class of evolutionarily conserved genes defined by piwi are essential for stem cell self-renewal

Germ-line stem cells (GSCs) serve as the source for gametogenesis in diverse organisms. We cloned and characterized the Drosophila piwi gene and showed that it is required for the asymmetric division of GSCs to produce and maintain a daughter GSC but is not essential for the further differentiation of the committed daughter cell. Genetic mosaic and RNA in situ analyses suggest that piwi expression in adjacent somatic cells regulates GSC division. piwi encodes a highly basic novel protein, well conserved during evolution. We isolated piwi homologs in Caenorhabditis elegans and humans and also identified Arabidopsis piwi-like genes known to be required for meristem cell maintenance. Decreasing C. elegans piwi expression reduces the proliferation of GSC-equivalent cells. Thus, piwi represents a novel class of genes required for GSC division in diverse organisms.

[Research on the regulation of glucoamylase gene(glaA) expression in A. niger. II. Analysis of the function of 5'-regulatory region of A. niger T21 and 3.795 glaA gene]

Two plasmid vectors pXH2 and pGH1 were constructed through the fusion of E. coli hph gene, the report gene and the 5' upstream regions of A. niger T21 and 3.795 respectively, as well as the terminator of A. nidulans trpC gene. The plasmid vectors were than used to transform A. niger T21 to functionally identify those different basic groups between the two 5' upstream regions responsible for high-level expression of the glaA gene. Southern analysis of two transformants XH2C and GH1C revealed that pXH2 and pGH1 were integrated respectively into the chromosome at same site with two copies in tandem array. The level resistant to HmB(3000 micrograms/ml) of XH2C was twice as high as that (1500 micrograms/ml) of GH1C, indicating that the changes of basic groups through mutation result in twice increase of functional level of region responsible for transcription and regulation of A. niger T21 glaA gene compared with that of 3.795.

[Studies on the regulation of glucoamylase gene (glaA) expression in A. niger I. The overall analysis and comparison of the expression of glucoamylase in the overproducing strain A. niger T21 and its original strain A. niger 3.795]

Expression of the A. niger T21 and 3.795 glaA gene was investigated with respect to the growth of mycelia, producing of glucoamylase, copy number of glaA gene as well as glucoamylase mRNA level and its stability. Both A. niger T21 and 3.795 produced substantial glucoamylase at the stable phase when their biomass were the same. After incubating for 72 hours, while the biomass remained the same, the glucoamylase produced by T21 was 10-17 times higher than that by 3.795. Northern analysis showed that in the total RNA from T21 4.3-4.4 fold as much glucoamylase mRNA as from 3.795 was determined. This result along with results with regard to copy number of glaA gene and stability of glucoamylase mRNA supported the suggestion that the increased mRNA level of glucoamylase was contributed by the increasing at transcription level. The inconsistancy between the difference of enzyme production (10-17 fold) and that of the mRNA level (4.3-4.4 fold) revealed that some difference at translation exist probably. Furthermore, expression of both T21 and 3.795 glaA gene was regulated by carbon sources, this regulation occurred at transcription level in the same manner and also probably occurred at translation level.

Polymorphism of angiotensin I converting enzyme gene in the older Chinese: linked to ambulatory blood pressure levels and circadian blood pressure rhythm

This study was undertaken to evaluate the association of polymorphism of angiotensin I converting enzyme (ACE) gene with causal and ambulatory blood pressure in the Chinese population. Genomic DNA was amplified by polymerase chain reaction (PCR) using primers flanking the polymorphic region in intron 16 of the ACE gene. Alleles were detected on agarose gels stained with ethidium bromide. Causal blood pressure was measured in the 133 normotensive and 122 essential hypertensive subjects; of the essential hypertensive subjects, 65 patients underwent non-invasive ambulatory blood pressure. There was no significant difference of ACE genotype and allele frequencies between the hypertensive and normotensive subjects. Non-significant differences were demonstrated in gender, age, causal blood pressure according to the ACE gene genotypes in the 65 patients who underwent non-invasive ambulatory blood pressure; however, effects of the ACE gene genotypes were observed on the derivatives of ambulatory blood pressure, including sleeping blood pressure levels and circadian blood pressure rhythm (p < 0.05). We suggest that insertion/deletion polymorphism of the ACE gene should be associated with blood pressure and ambulatory blood pressure might be superior to causal blood pressure at the molecular level.

Effect of 24-h blood pressure levels and circadian blood pressure rhythm on left ventricular structure and function in isolated systolic hypertension

Forty-one participants (mean age 69 +/- 5.6 years) were examined by fully automatic blood pressure monitor and Doppler echocardiography to gain information on the ambulatory blood pressure and the left ventricular structure and function in isolated systolic hypertension. Cumulative sum (cusum)-derived statistics was used to quantify circadian blood pressure rhythm and 24-h blood pressure levels were defined as mean blood pressure values during 24 h, waking (06:00-22:00 h) and sleeping (22:00-06:00 h) periods, respectively. Most of the derivatives of ambulatory blood pressure, including cusum-derived statistics and 24-h blood pressure levels, were significantly related with the left ventricular structural (left ventricular posterior wall and interventricular septum thickness) and functional (acceleration time in the left ventricular outflow tract and early diastolic deceleration time) indexes. Among the left ventricular structural and functional indexes, interventricular septum thickness at end diastole had the strongest correlation with sleeping diastolic mean blood pressure (r = 0.41, P < 0.01), left ventricular posterior wall at end diastole, the best with 24-h systolic mean blood pressure (r = 0.41, P < 0.01), acceleration time the strongest with systolic cusum-derived circadian alteration magnitude (r = 0.49, P < 0.01) and early diastolic deceleration time the greatest with diastolic cusum-derived trough blood pressure (r = 0.45, P < 0.01). We conclude that left ventricular structural changes rely on 24-h systolic and diastolic blood pressure levels, whereas left ventricular functional variations may be more dependent upon circadian blood pressure rhythm in elderly patients with isolated systolic hypertension.